Apparatus for machining blast furnace hopper ring in place on the furnace

ABSTRACT

Portable machining apparatus to be mounted in the top of a blast furnace for milling a level surface on a blast furnace hopper ring to enable a gas-tight seal to be formed between the blast furnace stack and the large bell hopper. This prevents flue gas and entrained solids from escaping into the atmosphere. The apparatus includes means for moving the cutting head circumferentially, radially, vertically and horizontally.

United States Patent Harris 1 Aug. 29, 1972 [54] APPARATUS FOR MACHINING BLAST FURNACE HOPPER RING IN PLACE ON THE FURNACE 2,016,574 10/ 1935 Myers et a1. ..90/12 R 3,175,465 3/1965 Fuller et ..90/12 R 3,386,337 6/1968 Spier ..90/12 R 3,477,341 11/ 1969 Rickenbrode ..90/ 12 R Primary Examiner-R. Spencer Annear Attorney-Ralph H. Dougherty [57] ABSTRACT Portable machining apparatus to be mounted in the 52 us. 01. ..90/12, 266/1 R P blast filmace' for milling a level Surface on a [51] 1111, C1. ..B23c 1/20 blast furnace pp ng to enable a gas-tight seal to [58] Field of Search .266/1 R- 90/12 R be firmed between the blast furnace stack and I I large bell hopper. This prevents flue gas and entrained solids from escaping into the atmosphere. The ap- [56] References Clted paratus includes means for moving the cutting head UNITED STATES PATENTS circumferentially, radially, vertically and horizontally.

3,603,204 9/ 1971 Anderson et a1 ..90/12 R 7 Claims, 4 Drawing 50 63 Patented Aug. 29, 1972 2 Sheets-Sheet 2 INVENTOR. LEONARD E HARRIS A r rarney APPARATUS FOR MACHINING BLAST FURNACE HOPPER RING IN PLACE ON THE FURNACE This invention relates to the maintenance of a blast furnace and more particularly, to apparatus for machining a blast furnace hopper ring in place on the blast furnace. The shell of a conventional blast furnace is topped by a truncated cone called a top cone. The bottom of the cone is welded to the top of the main shell structure. The top opening in this top cone receives a lip ring or hopper ring which is usually bolted to the top cone. The hopper ring must be located concentrically with the stack as it provides a seat for the large bell hopper and supports other filling equipment on the top of the furnace.

During a blast furnace campaign, the hopper ring becomes enlarged and warped by the expansion and contraction resulting from the high operating temperatures of the furnace. When a furnace is taken out of production for repair and reline, the large bell hopper is removed, but the hopper ring remains in place as an integral part of the furnace. However, before the large bell hopper can be replaced, the hopper ring must be reconditioned to insure a gas-tight seal between the hopper and the hopper ring.

Heretofore it has been the practice to build up uneven and low spots of the ring with inserts and weld material, then to hand-grind the seat surface of the ring in an attempt to make it level or at least acceptable. This method is not only slow, inefficient and expensive but also fails to achieve a sufficiently gas-tight seal to prevent the escape of gas and flue dust into the atmosphere.

The primary object of the present invention is to provide an apparatus that will machine a true and level surface on a blast furnace hopper ring for the support of a hopper and bell superstructure.

It is also an object of the present invention to provide a level sealing surface that will afford a gas-tight seal which will prevent flue gas and entrained solids from escaping from the interior of a blast furnace between a large bell hopper and a hopper ring.

It is a further object to provide an apparatus which also may ream vertical bolt holes in a blast furnace hopper ring.

I have invented a portable apparatus for machining a blast furnace ring, which apparatus is positioned in the hopper ring after the large bell hopper and superstructure have been removed therefrom. This apparatus then machines the hopper seat of the ring to a true and,

level surface. It is also capable of reaming holes in the hopper ring that may have become clogged during the blast furnace campaign.

In the drawings:

FIG. 1 is a vertical-sectional view of a blast furnace stack, top cone and large bell hopper.

FIG. 2 is a vertical-sectional view of my machining apparatus along line Il-II of FIG. 3.

FIG. 3 is a horizontal-sectional view of my apparatus along line III-III of FIG. 2.

FIG. 4 is a horizontal-sectional view of a portion of the apparatus taken along line IV-IV of FIG. 2.

As shown in FIG. 1, blast furnace shell has affixed to it, at its top, a top cone 12 with associated hopper ring 14. This hopper ring provides a seat for large bell hopper 15. As better shown in FIG. 2, the hopper ring includes an inward projection 16 and a hopper seat 17.

This hopper seat is a critical surface which must be machined to a true and level plane. My machining apparatus comprises a base 18 which fits in the opening of the hopper ring, a carriage and milling cutter, and means connected to the carriage for moving the cutter in all directions. As shown in FIGS. 2 and 3, base 18 includes a plurality of structural support members 19 such as wide flange beams radiating from a central point to form a spider web-like structure. The bottom of the end of each beam is fitted with a pair of adjusting screws 20 for leveling the base. The two screws are on opposite sides of the beam web. Threaded back-up blocks 21 are welded inside each beam to provide sufficientthread contact area to support the structure. A circular base plate 23 having an upstanding central boss 24 is welded to beams 19 to place the boss 24 in the exact center of the frame. The outer circumferential edge of the base plate is machined to a true circle and carries a ring 26 which supports a roller chain 27. Each of these parts is welded into position to form a large gear. A carriage base 30 having a hub 31 is joumaled on boss 24. The hub is fitted with a bronze bushing 33 and a grease fitting 34. The carriage base is retained in place on the boss by hub cap 36. The carriage base has arcuate bronze bearing segments 38 and 39, which fit into grooves machined in its bottom surface and ride on the base plate 23. The top of carriage base 30 has radial ways 41 which act as guides for a carriage assembly 42. The carriage assembly includes an upstanding front panel 45 which has a window 46. A transverse dove tail slide 47 projects forwardly from the lower portion of the panel.

As shown in FIG. 2, panel 45 carries a vertical drive assembly 50 which includes a vertical plate 51 having an opening 52. A dove tail recess 54 extends horizontally across the plate 51 and slidably receives the dove tail slide 47. The top of plate 51 carries a bracket 55 of inverted L-shape. Bracket 55 is vertically spaced from plate 51 slidably receiving the upper edge of panel 45.

Bracket 55 carries a shelf 56 on which are mounted a vertical drive motor 57 and speed reducer 58. The speed reducer is connected to the drive motor by drive shaft 59 and coupling 60. A right angle gear box 62 is mounted atop bracket 55 and is connected to speed reducer by drive shaft 63 and coupling 64. Drive screw 66 extends downwardly from the gear box through fixed nut 67 and terminates in a thrust bearing 68 which is connected to the bottom of plate 51. Clearance for the drive screw is milled into the face of plate 51.

Cutter mounting assembly 70 includes a vertical front plate 71, wings 72 joined to opposite side edges of plate 71, and a shelf 73 joined to the lower edges of the wings. Vertical guide members 75 (FIG. 3) fixed to the inside faces of the wings form a pair of guideways with the front plate 71. These guideways slidably receive the side edges of plate 51. Milling cutter assembly 76, which has a cutting head 77, is attached to front plate 71 by recessed bolts (not shown). A suitable cutter assembly is manufactured by Ingersoll Milling Machine Company of Rockford, Illinois. Variable speed cutter drive motor 70 is supported by and is attached to shelf 73. The cutter is connected to drive motor 79 by drive shaft 80 and coupling 81.

A horizontal drive motor mounting bracket 84 indicated in FIG. 3 extends upwardly from one of the wings 73. Mounted thereon is a small drive motor 85 and speed reducer 86 having a sprocket 87 on which drive chain 88 is engaged. As shown in FIG. 4, a horizontal drive screw 89 having a drive sprocket 90 is journaled in thrust bearing blocks 91 which are vertically movable in ways 92 which are fixed to panel 45. A bar 93 is fixed horizontally between wings 72. A fixed nut 94, in which drive screw 91 turns, is attached to bar 93.

Carriage assembly 42 is connected to carriage base 30 by a radial adjusting screw 100 having a crank 101. Threaded pedestal 102 is mounted on the base of carriage assembly 42 and receives the threaded end of screw 100. The crank end of the screw is journaled in a pillow block 103. Collars 104A and 104B are fixed to screw 100 on each side of pillow block 103. If desired, adjusting screw 100 can be motorized.

The entire assembly above base 18 is arcuately driven by means mounted on carriage base 30. This arcuate drive means comprises a hydraulic power unit 107 which is hydraulically connected to hydraulic motor 108. Drive shaft 109 connects the motor to a right angle speed reducer 1 from which sprocket 112 extends downwardly. This sprocket engages chain 27 which is fixed to base plate 23 as previously described.

When a furnace is taken out of production, the large bell hopper is removed along with the superstructure. The machining apparatus is hoisted into place and seated on projection 16 of hopper ring 14. Base 18 is leveled by adjusting screws 20. The center of boss 24 is aligned with the center line of the furnace. Cutter head 77 is attached to cutter assembly 76 and raised to a sufficient height to clear the point of highest elevation on hopper seat 17. This is accomplished by actuating motor 57 which through associated drive shaft 59, coupling 60, speed reducer 58, drive shaft 63, coupling 64 and right angle gear box 62 causes drive screw 66 to rotate. Nut 67, being fixed to front plate 71, moves upwardly on drive screw 66 raising the entire cutter mounting assembly 70.

Cutter head 77 is moved radially to the proper location by rotating radial adjusting screw 100 which causes the entire carriage assembly to move radially outward along ways 41.

Cutter drive motor 79 is started. Cutter head 77 is lowered until it contacts the highest point on hopper seat 17.

Arcuate drive motor 107 is a self-contained electrically driven pump and motor combination having a cooler, reservoir, etc., which provides hydraulic power for motor 108. This unit is energized to cause motor 108, through speed reducer 110, to rotate sprocket 112, the teeth of which engage roller chain 27, causing base plate 23 and all associated structure including the cutter to move circumferentially. The base plate may be driven in either clockwise or counterclockwise rotation.

The hopper ring 14 has bolt holes 115 for aligning the hopper 15 with the hopper ring. My machining apparatus can be used for reaming these bolt holes merely by substituting a drill or reamer for cutting head 77. To position a reamer accurately, the horizontal drive means is utilized. Drive motor 85 through speed reducer 86 drives sprocket 87. Power is transmitted to drive screw 89 to drive chain 88 and sprocket 90. When the drive screw 89 rotates in fixed nut 94, which is efiectively attached to cutter mounting assembly 70, it causes said mounting assembly to move horizontally with respect to upstanding front panel 45. Dove tail 47 is movable in dove tail recess 54 and the vertical drive assembly support is in slidable engagement with the top of panel 45. The reamer is positioned roughly by the radial adjusting screw and arcuate drive. The horizontal drive allows fine adjustments to be made.

My machining apparatus can be used on blast furnaces of various diameters. The only part that must be modified is the base framework. If a hopper ring has no inward projection 16 as indicated in FIG. 2, a series of brackets may be welded inside the ring to provide support for the frame.

It can readily be seen from the foregoing that l have invented an apparatus that will machine a true and level surface on a blast furnace hopper ring. This apparatus enables the machining of the ring to be done more accurately and in much less time than was heretofore possible. It also provides a quick and easy means of reaming hopper ring bolt holes.

lclaim:

1. A milling machine comprising:

a base having an upstanding boss centered thereon;

a support plate journaled on said boss;

at least one bearing member between said base and said support plate radially spaced from said boss for supporting the entire support plate weight directly on said base;

radial ways carried by said support plate;

a carriage mounted on said ways;

means connected to said support plate and said carriage for moving said carriage radially;

a cutter assembly mounted on said carriage and having a cutting head;

means supported by said carriage for rotating said cutting head;

means supported by said carriage for moving said cutting head vertically;

means supported by said carriage for moving said cutting head tangentially; and

means connected to said support plate for moving said cutter assembly arcuately.

2. Apparatus as defined in claim 1, in which said means for moving said carriage radially comprises:

a pillow block fixed to said support plate;

a pedestal fixed to said carriage and having a threaded hole therethrough;

an adjusting screw journaled in said pillow block and threadedly engaged with said pedestal; and

means for rotating said screw to move said carriage radially along said ways.

3. Apparatus as defined in claim 9 in which said means for rotating said cutting head comprises a variable speed drive motor mounted on said cutter assembly.

4. Apparatus as defined in claim 1 in which said means for moving said cutting head vertically comprises:

drive means mounted on and horizontally movable with respect to said carriage; a drive nut fixed to said cutter assembly; and

6 a vertically mounted drive screw depending from direction.

said drive means and threadedly engaged with said 6. Apparatus as defined in claim 1 including means drive nut, whereby rotation of said drive screw attached to said base for leveling said base. causes vertical movement of said cutter assembly. 7. Apparatus as defined in claim 1 in which said 5. Apparatus as defined in claim 1 in whi h aid 5 means for moving said cutter tangentially comprises: means for moving said cutter assembly arcuately comdrlve means ppo y sald c e assembly; prises: a horizontal drive screw journaled on said carriage,

a gear fixed to and concentric with said base; d Connected to Sald means; and a pinion gear meshed with said first-named gear and 3 We fixed to cutfer assembly and havi a h ft; d 10 threadedly engaged with said drive screw, whereby means connected to i support plate. and said rotation of said drive screw causes tangential pinion gear shaft for rotating said pinion gear in movement ofsald cutter assemblyboth a clockwise and a counterclockwise 

1. A milling machine comprising: a base having an upstanding boss centered thereon; a support plate journaled on said boss; at least one bearing member between said base and said support plate radially spaced from said boss for supporting the entire support plate weight directly on said base; radial ways carried by said support plate; a carriage mounted on said ways; means connected to said support plate and said carriage for moving said carriage radially; a cutter assembly mounted on said carriage and having a cutting head; means supported by said carriage for rotating said cutting head; means supported by said carriage for moving said cutting head vertically; means supported by said carriage for moving said cutting head tangentially; and means connected to said support plate for moving said cutter assembly arcuately.
 2. Apparatus as defined in claim 1, in which said means for moving said carriage radially comprises: a pillow block fixed to said support plate; a pedestal fixed to said carriage and having a threaded hole therethrough; an adjusting screw journaled in said pillow block and threadedly engaged with said pedestal; and means for rotating said screw to move said carriage radially along said ways.
 3. Apparatus as defined in claim 1 in which said means for rotating said cutting head comprises a variable speed drive motor mounted on said cutter assembly.
 4. Apparatus as defined in claim 1 in which said means for moving said cutting head vertically comprises: drive means mounted on and horizontally movable with respect to said carriage; a drive nut fixed to said cutter assembly; and a vertically mounted drive screw depending from said drive means and threadedly engaged with said drive nut, whereby rotation of said drive screw causes vertical movement of said cutter assembly.
 5. Apparatus as defined in claim 1 in which said means for moving said cutter assembly arcuately comprises: a gear fixed to and concentric with said base; a pinion gear meshed with said first-named gear and having a shaft; and means connected to said support plate and said pinion gear shaft for rotating said pinion gear in both a clockwise and a counterclockwise direction.
 6. Apparatus as defined in claim 1 including means attached to said base for leveling said base.
 7. Apparatus as defined in claim 1 in which said means for moving said cutter tangentially comprises: drive means supported by said cutter assembly; a horizontal drive screw journaled on said carriage, and connected to said drive means; and a drive nut fixed to said cutter assembly and threadedly engaged with said drive screw, whereby rotation of said drive screw causes tangential movement of said cutter assembly. 